Attempting to declare multiple variables on one line will throw an error when you attempt to "Check" the VB Script, but will be fine if you accept and then run the script:

Dim Var1, Var2

"Function [Var2] is invalid."

From https://msdn.microsoft.com/en-us/library/t7zd6etz(v=vs.84).aspx

You declare multiple variables by separating each variable name with a comma. For example:

Dim Top, Bottom, Left, Right

Dim Top, Bottom, Left, Right